import java.sql.*;

public class Main {
    public static void main(String[] args) {

        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;

//1.加载驱动

        try {
            Class.forName("com.mysql.cj.jdbc.Driver");


            //2.创建连接
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            connection = DriverManager.getConnection(url, "root", "huang123");
            /*if(connection != null){
                System.out.println("连接成功");
            }*/
            //3.写sql
            String sql = "select * from user";

            //4.预编译sql
            preparedStatement = connection.prepareStatement(sql);

            //5.执行sql
            resultSet = preparedStatement.executeQuery();


            //6.遍历结果
            while (resultSet.next()) {
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id + "----" + name + "----" + pass);
            }


        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        } finally {
//7.关闭资源

            try {
                if (resultSet != null) {
                    resultSet.close();
                }
                if (preparedStatement != null) {
                    preparedStatement.close();
                }
                if (connection != null) {
                    connection.close();
                }
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }
    }
}